Four flap opener for cases



Dec. 21, 1965 B. J. NIGRELLI ETAL FOUR FLAP OPENER FOR CASES 5 Sheets-Sheet 1 Filed June 4, 1962 GI I-UIEIEIEIRISISIRI mm!- 3 cu m INVENTORS ammo J. NIGRELLI WENDELL E. STANDLEY RICHARD awnmmn DONALD 0. KING 5. BY ATTORNEY QQQQQ &&Q r yea a Dec. 21, 1965 B. J. NIGRELLI ETAL FOUR FLAP OPENER FOR CASES 5 Sheets-Sheet 2 Filed June 4, 1962 INVENTORS BIAGIO J. NIGRELLI WENDELL E. STANDLEY RICHARD B. WITTMANN DONALD D. KING AT TOR N EY Dec. 21, 1965 B. J. NIGRELLI ETAL FOUR FLAP OPENER FOR CASES 5 Sheets-Sheet 3 Filed June 4, 1962 INVENTORS BIAGIO J. NIGRELLI 1 WENDELL E. STANDLEY RICHARD a. wrr'rmmn DONALD 0. KING 4 BY ATTORNEY Dec. 21, 1965 B. J. NIGRELLI ETAL 3,224,165

FOUR FLAP OPENER FOR CASES Filed June 4, 1962 5 Sheets-Sheet 4 INVENTORS BIAGIO J. NIGRELLI WENDELL E. STANDLEY RICHARD B. WITTMANN DONALD D. KING 5 L6 ATTORNEY Dec. 21, 1965 B. J. NIGRELLI ETAL FOUR FLAP OPENER FOR CASES 5 Sheets-Sheet 5 Filed June 4, 1962 INVENTORS BIAGIO J. NIGRELLI WENDELL E. STANDLEY RICHARD B. WITTMANN DONALD D. KING ATTORNEY United States Patent 3,224,165 FOUR FLAP OPENER FOR CASES Biagio J. Nigrelli, Northbrook, Wendell E. Standley, Lake Forest, and Richard B. Wittmann, Chicago, IlL, and Donald D. King, Madison, Wis., assignors, by mesne assignments, to Johns-Nigrelli-Johns, Inc., Skokie, 11]., a corporation of Illinois Filed June 4, 1962, Ser. No. 199,944 8 Claims. (Cl. 53382) The present invention relates to case opening machines and more particularly to machines for lifting and swinging outward the cover flaps on rectangular paperboard containers or cases.

A principal object of the invention is to provide a machine of this type for opening the underlying cover flaps of a four-flap case after the two top flaps have been opened.

A further object of the invention is to provide an improved machine for opening cover flaps of a case while a case is being advanced on a conveyor, such flaps being hinged to the case along hinge lines extending transversely to the path of travel of the case.

A further object of the invention is to provide an improved case opening system for advancing four-flap type cases along a path and opening one or more flaps carried on hinge lines parallel to the path of travel and subsequently opening underlying flaps hinged on lines extending transversely to the path of travel.

A still further object of the invention is to provide improved case feeding and conveying means for a case opening system designed to open both overlying and underlying flaps, the feeding and flap opening mechanisms being controlled to operate in synchronous relations.

Additional and more specific objects and advantages of the present invention will become apparent as the description proceeds.

In the drawings, illustrating a preferred embodiment of the invention,

FIGS. 1 and la, taken together, show the machine in side elevation, FIG. 1 showing the receiving end portion having a two-flap opening station for overlying flaps hinged on line parallel with the path of travel, and FIG. 1a showing the discharge end portion of the machine having a two-flap opening station for opposite case flaps hinged on lines transverse to the path of travel;

FIG. 2 is a fragmentary plan view showing the receiving end of the case conveyor;

FIG. 3 is an end view of the machine, with parts omitted, looking toward the left as viewed from the discharge end of the machine as shown in FIG. 1a;

FIG. 4 is a vertical sectional view taken approximately along line 4-4 of FIG. la;

FIGS. 5 to inclusive are fragmentary, schematic views showing the operating sequence of the mechanism for lifting and swinging the leading and trailing case flaps to an outwardly extended position; and

FIG. 11 is a diagrammatic illustration of the wiring and control devices.

The machine in its preferred form is designed to receive cases of the type having four-flaps which are being conveyed in an extended row in which the cases are underlying flaps are on end walls extending transversely to such path. In the present instance, the cases are fed singly to an auxiliary speed-up conveyor operating at a faster rate than the principal conveyor. This auxiliary conveyor delivers the cases singly to the first station where the overlying or side flaps are raised and swung partially upward. The case is then engaged by pushers on the principal conveyor and advanced past plow means to swing the side flaps to a laterally extended position.

As soon as the side flaps are swung to their laterally extended positions the case is delivered to the station where the leading and trailing flaps are lifted. As the ease advances beyond the point where these flaps are lifted, other devices engage and control the fiaps to move them to forwardly and rearwardly extended positions where they pass beneath hold-down members and are then conducted beyond the machine to stations, not shown, where the cases are either filled or emptied of their contents, whichever is desired.

Referring more particularly to the drawings, FIG. 1 and 1a, taken together, show the principal parts of the machine. A suitable base frame, having horizontal members 1, 1 and 2, 2 and vertical members 3, 3, serves to support the principal conveyor, indicated as a whole at 4. Cases 5, 5 are advanced to conveyor 4 from an abutted row held on a conveyor 6 which may be supported on separate frame members, not shown. A receiving conveyor, indicated as a whole at 7, and having a greater speed than conveyor 4, first receives a case and moves it to the first treating station, indicated as a whole at 8. At this station the long side flaps of the case are raised and then swung outwardly by plow means, indicated as a Whole at 9.

The conveyor 4 then moves the case from treating station 8 toward a second treating station 10 for raising the underlying leading and trailing flaps. The delivery of a case to the station 10 is atfected by a speed-up conveyor 11 similar to conveyor 7.

Cases of various sizes and shapes may be handled. The case 5, herein illustrated, is a twenty-four can size formed of sturdy, resilient paperboard, such as corrugated board or solid fibre board. The flaps 12, 12, hinged on the longer walls 13, 13, usually have a dimension at right angles to their hinges so that these flaps will meet centrally of the case. The flaps 14, 15 on the end walls 16 and 17 usually have the same length, measured from the hinges, as the flaps 12, 12. These flaps thus terminate short of the case center line, as measured between the end walls.

Case delivery The cases 5, 5 are preferably accumulated in end to end abutted relation on conveyor 6 which may comprise a series of live rolls 20, 20, continuously driven While the machine is being operated. The leading case of the abutted row is held from forward movement by a fixed stop 21 which preferably has an idle roll 22 journalled at its upper end. Cases are released one at a time by means of a releasing element 23 suitably mounted on the end of a piston rod 24 having a piston operating in cylinder 25 secured to the base frame. The releasing element may be shaped as a yoke carrying at its upper end a roll 26. In its lowered position the element 23 will be located so that the roll 26 will be aligned with rolls 20.

When a case is to be released, suitable control means to be described later will admit fluid pressure to the cylinder below the piston and lift the forward end of the leading case out of its holding contact against the roll 22 and the pressure of the cases behind the leading case, due to the action of the live rolls, will force the leading case forwardly. The control means for the piston 24 will cause lowering of the piston as soon as the leading case begins to move over roll 22. Thus, the release element will return to its lowered position before the leading end of the next case reaches the roll 26. This next case will then come to rest over the roll 26 and with its forward end against the stop roll 22.

ping effect on the bottom surfaces of the cases.

Conveyor construction First referring to conveyor 4, this comprises a pair of spaced sprocket chains 30, 30 passing over sprockets 31, 31 and 32, 32 at opposite ends of the base frame. The sprockets 32, 32 are mounted on shaft 33 journalled in suitable bearings carried on the base frame members. The shaft 33 carries a sprocket 34 thereon driven by motor 35 through sprocket chain 36. The sprockets 31, 31 at the receiving end of the conveyor are mounted on shaft 37 journalled on the base frame. It is be understood that suitable reduction gearing may be interposed between the motor and the parts driven thereby, if such is found necessary or desirable.

The speed-up receiving conveyor 7 for the lateral swinging flap opening station, includes the belt 28, above referred to, which passes over rollers 40 and 41 on shafts 42 and 43, journalled in longitudinally extending frame members on the base frame. See FIGS. 1 and 2. The driving means for the conveyor 7 comprises a sprocket 44 fixed on the end of shaft 37. A sprocket chain 45 passes over sprocket 44 and over a small sprocket 46 keyed on the end of shaft 43. By this arrangement the belt 28 is driven at a higher lineal speed than the chains 30, 30.

The sprocket chains 30, 30 support a plurality of spaced push rods 47, 47 to contact the trailing walls of the cases and propel the cases from the flap raising mechanisms past the folding and swinging devices to bring the flaps to outwardly extended positions. As shown in FIGS. 1 and 1a, the sprocket chains are supported in laterally positioned guide channels 48 in guide members 49. The

lower runs of the chains may be supported beneath the conveying level by rails 50.

The movement of releasing element 23 to release a case for transfer to the speed-up conveyor 7 is so synchronized with the push rod travel that a case will be moved onto the speed-up conveyor as the push rod for such case is moving upward around sprocket 31, substantially as shown in FIG. 1. As the case reaches conveyor 7, and is then .advanced by such conveyor, it is propelled onto the dead plate 29 and comes to rest upon this plate. T o insure a .maximum degree of accuracy a pair of yieldable, springloaded stops are located at the edge of the dead plate to engage the front wall of the case. One of these stops is indicated at 51 in FIG. 1. When the push rod reaches the trailing end of the case the front wall bears forcibly against the stops and displaces them to a position where vthey will bear against the case side walls and return to holding position as the case passes beyond the stops.

As shown in FIG. 1, the end of conveyor 7 is separated sufficiently from the case stop 21 to allow free passage 'of the push rods 47' upward through such space.

Opening of laterally hinged flaps The l-ateraly hinged flaps are preferably lifted by vacuum cup mechanism, as indicated generally at 8, and the flaps are swung to outwardly extended position by plow downwardly but are constructed so as to swing upwardly away from the top of the case. By forcing the frames downwardly and at the same time activating the vacuum cups, the arms move down while maintaining their horizontal positions. The vacuum cups grip the flaps and, as the frames continue their downward movement, the arms contact the hinge lines of the flaps and begin to swing upwardly about such hinge lines, thus raising the flaps to an angular position, which, in practice, is about 35 to 45 above the level of the case top.

The vacuum cups are mounted in their arms so as to be slidable at right angles to the arms. Thus, while the cups are gripping the flaps, the case may be advanced. Advantage is taken of this feature by advancing the case to a'member which engages beneath the leading edges of the raised flaps. As soon as the flaps are under the control of the plow, the vacuum is cut from the cups and they are returned by spring action to their original position. Concurrently, the arm supporting frames are raised out of contact with the flap hinges so that the case may advance freely past the flap raising mechanism. As the case continues to advance the plow swings the flaps to an outwardly extended position.

In FIG. 1 only the set of vacuum cups on the far side of the machine is shown. The laterally hinged flap 12 on the near side of the case has been omitted. The vacuum cups 54, 54 are shown in gripping relation to the flap on the far side of the case and the flap has been raised to an angle at which its leading edge portion will clear the plow 9 when the case is advanced. The cups 54 are supported on a metal tube 55 slidably mounted in .guide'elements 56, 57 carried on the free end of an upwardly swingable arme 58 pivoted on a vertically movable frame member 59 which may be raised and lowered by a piston rod 60 having a piston thereon operating in cylinder 61 which is secured on an upstanding frame member 62 fixed on the base frame. The swingable arm 58 carries a supporting element 63 having a slot in which is received a pin 64 fixed onto the tube 55. A coil spring 65 has one end secured to the pin 64 and its other end anchored to a lug 66 on the supporting element 63. By this arrangement the cups, when gripping the case flap, may be carried forward a short distance as the case advances and, when vacuum is released from the cups, they will be returned to retracted position by the spring 65. The tube 55, as herein illustrated, serves as the conduit to the vacuum-source, not shown.

Control of vacuum to the cups and control of fluid pres- .sure to operate the piston and cylinder mechanism for raising and lowering the vacuum cup frame is timed with the travel of the push rods and will be described later. The control means serves to cause downward movement of the vacuum cup frame and activate the cups immediately after a case has been delivered in position on the dead plate 29. The frame is held in its lowered position, thus holding the flaps 12, 12 raised, until the push rod 47, arriving behind the case, advances the case a short distance so that the flaps can be engaged by plow 9. The control then cuts off the vacuum and causes the piston in cylinder 61 to move upward to raise the vacuum cup frame out of contact with the case. The cups are immediately returned to their original position by the spring.

As the cases advance past the plow 9 the laterally hinged flaps are swung to their fully extended horizontal position. Shortly before the flaps are fully extended the case arrives at the second speed-up conveyor 11 and is moved in advance of its push rod and to a position at rest on dead plate 69. The drive for conveyor 11, as herein shown, may comprise a sprocket 11a on the motor shaft driving a chain 11b passing over a small sprocket on the shaft which carries the forward belt roller of conveyor 11.

Leading and trailing flap openers As the case arrives on the dead plate 69 it comes to a stop against a pair of yieldable stops, one of which is 5 indicated at 70. These stops, like the stops at the first station, are spring loaded and may readily be deflected when the box is propelled against them by the push rods 47.

After the case comes to a stop a pair of vacuum cups 71 and 72, depending from flexible hose sections 71a and 72a, are lowered into contact with the trailing and leading case flaps 14 and 15. The cups are activated and immediately raised and held briefly in raised position, as shown in FIG. 1a.

The hose sections 71a and 72a have at their upper ends an elbow fitting, indicated at 73 and 74, by which the hose sections are connected to additional hose sections 75 and 76 connected in turn to the vacuum feed line at 77. Each elbow fitting is attached to the end of a piston rod, indicated at 78 and 79, having thereon pistons operating in cylinders 80 and 81. These cylinders are secured to an adjustable frame member 82 carried on upstanding frame section 83 attached to the base frame.

After the flaps have been raised, and while being held by the vacuum cups, the push rod 47 again contacts the trailing case wall and begins to propel the case along the dead plate and past stop 70. The raised flap 14, being moved forward with the case, advances to a position where its leading free edge will be in contacting relation with a rod 85 supported on the frame a short distance above the top edges of the case walls. The length and flexibility of the hose sections 71a and 72a readily permit the flaps to advance this distance without any tendency for the vacuum cups to be detached.

Means are provided also for retaining the leading flap 15 raised when the vacuum is cut off from the cup 72. For this purpose a short rod or pin 86, carried on an endless chain 87, moves into position beneath the free end portion of the flap.

As soon as the rod 86 moves into contacting position beneath the raised flap 15 and the end of flap 14 has moved above the rod 85 the vacuum cups are deactivated and will swing free of the flaps. When the flaps are released by the cups they will tend to swing down into contact with their respective rods.

After the cases advance beyond the plow member 9 the side flaps are in a substantially horizontal position and will continue to be held in fully extended position by a pair of hold-down bars 88, 88 extending forwardly from the second flap opening station.

wardly extended position and for holding the trailing flap during the period when the leading flap is being swung forwardly comprises the endless chain 87 carrying rod 86 above referred to for swinging the leading flap. This chain also carries a plurality of similar rods 89, 89 which arrive in position at the proper time to bear upon the trailing flap while in rearwardly extended position and to hold it in such position while the case is moving. The purpose of this endless chain mechanism is to keep these flaps sufliciently extended forwardly and rearwardly of the moving case so that they will move readily under the inclined portions 91 of the hold-down bars 92 at the discharge end of the machine. The inclined portions terminate in vertical ends secured to the frame section 83 and the forward ends of the bars are held by an inclined rod 92a anchored on the frame section 83.

As best shown in FIGS. 1a, 3 and 4, the endless chain 87 passes over sprockets 93 and 94 fixed on stub shafts 95 and 96 journalled in bearings carried on an adjustable frame member 97. This frame has interiorly threaded portions into which vertically disposed, threaded rods 98 and 99 are received. The end portions of each threaded rod are held in bearings on the upstanding frame section 83 and, by rotating these rods in unison, the frame 97 may be moved and held in the desired position. As shown in FIG. la, the sprocket 94 is journalled on a level above the sprocket 93 so that the lower run of the chain will be upwardly inclined in the direction of movement.

By an inspection of FIGS. 3 and 4, it will be noted that the rod 86 and all the rods 89, 89 project outward of the chain 87 only a short distance. The length of the rods is sufficient to enable them to engage and control the case flaps adequately but not of such length that they will come into contact with the hose section 72a of the vacuum cup 72 or with the inclined end 91 of the adjacent hold down bar 92.

The drive for chain 87 comprises a spur gear 100 fixed on shaft 96 meshing with a gear 101 carried on a short shaft 102 journalled on frame 97. This shaft has a sprocket 103 keyed on its end which is driven by a chain 104 passing over sprocket 105 keyed on the shaft 33 which carries the chain 30 for the principal conveyor. By this drive mechanism the chain 87 will be driven at a lineal speed substantially in excess of that of the principal conveyor chain 30. In the construction illustrated, a lineal speed of the chain 87 twice that of the chain 30 has proved satisfactory.

The action of the chain 87 with its extending rods may be understood by referring to FIGS. 5 to 10, inclusive, and FIG. la. FIG. 5 shows the flaps 14 and 15 after they have been raised to a satisfactory angle for the operation of the machine. At this point the push rod 47 has advanced almost to a position where it will contact the trailing case wall and begin to move the case forward. The case, while at rest, is so positioned that the leading edge of flaps 14 may be swung upward clear of the rod 85. For a like reason the chain 87 is so timed with the push rods 47 on chain 30 that the rod 86 on the chain 87 will not move to a position adjacent the free edge of flap 15 until this flap has been raised by its vacuum cups. This assures that the rod 86 will not interfere with the flap as it is being raised.

While both flaps are held raised by the vacuum cups the push rod 47 comes to a position against the case and begins to move it forward. The free end of flap 14 will then be moved forward sufficiently to be held by the rod 85 in the event the flap should move toward closed position and the rod 86 will move beneath the raised flap 15. At this point the vacuum may be released from the cups, allowing them to swing back to a free hanging position. FIG. la illustrates the various parts before release of vacuum and FIG. 6 shows such parts after such release.

As shown in FIG. 7, the rod 86 has advanced sufliciently to bring the flap 15 beyond a vertical position and flap 14 is approaching the vertical.

In FIG. 8 the flap 15 has reached an angle at which it is almost ready to be released to slip easily under the inclined ends 91 of the hold-down bars 92. The flap 14 has been swung down below the retracted vacuum cup 71 and, in passing such cup, the end of flap may brush harmlessly against it. The flexibility of the hose will permit the vacuum cup to move readily out of the way when contacted by the swinging flap.

In FIG. 9 the flap 15 is on the point of being released by the rod 86 and left under the control of the inclined section 91. The flap 14 is almost ready to pass from under the rod 85. At this point it is to be noted that the series of short rods 89, 89 is moving into position where the first of such rods is in flap contacting position.

In FIG. -10 the leading flap 15 has begun to move beneath the hold-down bars 92. The flap 14 has now passed beyond the rod 85 and is being contacted by the first of the series of rods 89. From this point until the last rod 89 contacts the flap it will be maintained rearwardly extended due to contact with one or more of these rods. By the time the last rod 89 leaves the flap, such flap is sufficiently close to the inclined hold-down section 91 that it cannot swing forward into case closing position.

Control of vacuum to the cups and control of fluid pressure to operate the piston and cylinder mechanism to raise and lower the vacuum cups is timed with the travel of the push rods. In the present instance the vacuum cup devices for raising the lateral swinging flaps are operated at the same time as those for raising the leading and trailing, underlying flaps.

Control system While various specific forms of controls may be employed to synchronize the various operations, it is preferred to employ a number of solenoid valves controlled from a central point by means of a slip-ring cylinder, a portion of which is indicated at 110 in FIG. 11. This cylinder may be connected by suitable gearing 111 to the shaft 33 driving the principal conveyor chain 30, the driving ratio being such that the cylinder 110 will make one revolution during the interval required for the chain 30 to travel the distance between successive push rods 47.

The cylinder 110 carries a number of segmented sliprings having provision for individual angular adjustment. Each slip-ring comprises a complete conducting ring on which a suitable contact element or brush will bear and, in addition, each ring has a conducting segmental portion joined integrally with the complete ring, with a brush aligned with the path of the conducting segment to bear thereon. The remainder of the ring in line with the conducting segment is non-conducting. Thus, when the second brush is bearing on the conducting segment, current will flow between the brushes. As the use of slip-ring controls is well known to those skilled in this art it is not deemed necessary to illustrate the exact position of the various segments of the slip-ring, and such segments will be indicated in their approximate positions.

Referring first to the feed mechanism for releasing cases from the abutted row of cases on the live rolls 20, 20, the control of fluid pressure to the cylinder 25 to raise and lower roll 26 is obtained through a solenoid valve 116, preferably of double solenoid, four-way type, the operation of which is controlled by two segmented sliprings-one for each solenoid-indicated at 117 and 1118.

The slip-ring 117 and contacting brush elements 117a and 11711 will close a circuit to the solenoid 116a of valve 116 when segment 117c passes beneath brush 117a. This circuit may be traced from ground connection 119, through the source of current 120, through wire 121, slip-ring 117 and its brushes, thence through wire 122, through the solenoid coil to ground connection 123. The valve spool will move toward solenoid 116a and admit fluid under pressure back of the piston in cylinder 25, raising roller and releasing the leading case in the row as previously explained. The current will be maintained during a very short interval but the piston will remain in raised position until the valve is reversed. This will be effected as soon as the leading portion of the case begins to move over roll 26. At this point segment 1180 will pass under its brush 118a completing a circuit from the current source, traced above, through the slip-ring and its brushes, then through wire 125, the winding of solenoid 11Gb and ground connection 126. Reversal of the spool of the valve admits fluid pressure in front of the piston and lowers the roller 26 so that the next oncoming case moves against the stop roller 22. The current flows only momentarily through the solenoid but the valve remains in position until again activated in the next cycle.

As previously pointed out the movement of the piston rod to release a case is timed With the push rod travel so that the case will move onto the speed-up conveyor 7 well in advance of the travel of push rod 47 up around sprocket 31. As will be brought out more clearly below,

.while one of the push rods 47 is moving up behind the case'being delivered to the speed-up conveyor 7, two additional push rods are moving cases beyond the first and second stations.

As soon as the speed-up conveyor 7 moves a case into position at the first flap raising station for the laterally swinging flaps the two sets of vacuum cups are ready to i be operated. This comprises admitting fluid pressure to 8 the two cylinders 61 to lower the vacuum cup frames against the hinges of the case flaps and, when the cups have contacted the flaps, such cups will be activated. Accordingly, slip-ring unit 127 will be positioned on the cylinder so that its operating segment 127a reaches the brush 127a immediately after the case is due to arrive in position. This actuates the solenoid 128a of valve 128 to admit fluid pressure to cylinder 61 and move the piston rod 60 and cup frames down.

At the time the cups 54 are due to contact the flaps, the solenoid valve 129 is actuated by slip-ring 130 to activate such cups. The cup frame continues to move downward a short distance so that the vacuum cup arms will pivot about the flap hinges. By the time the piston rod60 has reached the limit of its downward movement, the push rod 47 following the case catches up with the case and beings to move it forward. Since the cups are slidable on their swinging arms, they move forward a short distance with the case until the leading edges of the flaps are in contacting relation to the plow 9. The cups are deactivated at this point by slip-ring unit 131 to return the solenoid valve 129 to closed position. Following this, the solenoid valve 128 is actuated by slipring unit 132 to reverse this valve and raise the vacuum cup frame into position to be clear of the next following case.

The push rod 47 propels the case to the next speed-up conveyor 11 where the case is again advanced ahead of the push rod and comes to rest at the second flap raising station. The cylinders 80 and 81 for raising the vacuum cups are shown controlled in unison by one solenoid valve 135, although they may, if desired, be controlled separately. As soon as the case is due to stop at the second station the slip-ring unit 136 will have rotated to a position to close the circuit to the solenoid a admitting fluid to cylinders 80 and 81 to move downward the piston rods carrying the vacuum cups 71 and 72. At substantially the same time as the cups begin to move down the slip-ring unit 137 will have moved to complete the circuit through its brushes, energizing solenoid 138a of solenoid valve 138 and activating the cups 71 and 72 to grip the flaps 14 and 15.

Immediately after the flaps are gripped by the cups the slip-ring unit 139 will have rotated suificiently to close the circuit through its brushes to energize solenoid 1351) of valve 135 and cause the return of the cups to raised position. While the cups are thus raised, holding the flaps up, the push rod 47 will again catch up with the case and move it forward so that the lifted flaps will be brought under the control of the rods 85 and 86. The last slip-ring unit 140 will then have rotated to a position in which a circuit will be completed through its brushes to energize the solenoid 13812 and reverse the valve to cut off the vacuum to the cups. Thus the cycle is completed.

It is to be noted that the slip-rings 130, 131, 132 and 127 for controlling the vacuum and raising and lowering the cups at the first station operate concurrently with slip-rings 136, 139, 137 and 140 for similar purposes operating at the second station. While a given case is advanced past the two stations by the same push rod it is clear that successive push rods are at the same time moving cases forwardly at each of the two stations.

For simplicity of description the various parts of the cases and operating mechanism have been referred to as positioned or movable horizontally or vertically. It is desired that such description be considered solely for convenience and ease in understanding the principles of the invention and not in a limiting sense.

In the event cases having only two opposed flaps, instead of two outer and two underlying flaps, are to be handled by the machine, it is within the contemplation of the invention that one or the other of the sets of operating devices at the two stations may be held in inoperative position while the desired set is operating.

From the foregoing it is clear that the present invention provides effective means for handling conventional four-flap cases to open all four flaps and discharge the cases with such flaps fully extended so that the top of the case is entirely unobstructed, enabling the contents such as empty cans, to be easily removed. Or, if the cases are empty, they may readily be filled.

By so controlling the devices at the separate stations that the overlying flaps of one case will be raised and folded outwardly at the same time that the underlying flaps of a previously treated case are opened, maximum speed of handling is achieved.

While the present description sets forth a preferred embodiment of the invention, numerous changes may be made in the construction without departing from the spirit of the invention, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

We claim:

1. In a cover flap opening mechanism for a rectangular, fourwall, top-opening case formed of resilient paperboard and having cover flaps hinged on the upper edges of its walls, the combination of a base, a series of members on the base forming supporting means along which a case may be advanced along a fixed path, a principal conveyor having a plurality of case-engaging pushers spaced apart at a distance greater than the case dimension to move cases separately along such path, means for operating the principal conveyor at a constant speed, flap raising means for the trailing flap of a case, such means being located in operative relation to cases to be advanced, an auxiliary conveyor located upstream of the flap raising means, means for operating the auxiliary conveyor at a speed in excess of that of the principal conveyor, whereby a case moved by a pusher into operative relation to the auxiliary conveyor will be advanced substantially ahead of the pusher, means for stopping the case in operative relation to the flap raising means, and a fixed element for swinging a raised, trailing flap, said element being located at an appreciable distance downstream from the leading edge of such flap on a case stopped at the flap raising means to be clear of the flap while it is being raised, said fixed element serving to swing the flap toward its open extended position when the case is advanced relative to such element, and control means timed with the principal conveyor for actuating the flap raising means and for holding such means in operative condition until the oncoming pusher on the conveyor has reached and advanced the case a sufficient distance to enable the leading edge of the flap to engage such fixed swinging element.

2. In a cover flap opening mechanism for a rectangular, four-wall, top-opening case formed of resilient, foldable paperboard and having cover flaps hinged respectively on the upper edges of the leading and trailing case walls, the combination of a conveyor for advancing the case along a path transverse to the hinge lines of such flaps, means for driving the conveyor, separate raising mechanisms for the trailing and leading flaps aligned with such path, means for actuating said flap raising mechanisms to raise each of such flaps on a case approximately simultaneously, flap swinging means for the trailing flap, said swinging means being disposed above the case path and independent of the flap raising mechanism for first supporting the flap in raised position as the case is advanced, said means acting, upon further advance of the case, to swing the trailing flap over to a rearwardly extended position, swinging means for the leading flap, said means being disposed above the case path and movable in a path extending from a point above the case walls and leading flap, when in its closed position, to a point beneath the free edge portion of the raised flap and thence forwardly in the direction of conveyor travel,

stationary hold-down means located downstream of the conveyor travel for holding the leading and trailing flaps in open extended positions, means for moving the leading flap swinging means at a speed in excess of the speed of the case conveyor to swing the flap to a forwardly extended position and engage its free edge beneath such hold-down means, and a plurality of closely spaced hold-down elements for the trailing flap movable in the same path with the leading flap swinging means, and in delayed timed relation therewith, arranged to bear successively upon the rearwardly extended, trailing flap to hold it from swinging upward as the case advances, thereby to bring the flap so extended within engaging range of the stationary hold-down means to cause the trailing flap to slip beneath such hold-down means in a rearwardly extended position.

3. A conveyor system for rectangular cases and similar articles designed to deliver cases separately to and beyond a treating station, comprising, in combination, a base, a dead plate on the base for supporting cases to be treated, a principal conveyor on the base comprising spaced, endless sprocket chains carrying a plurality of spaced, transversely disposed push rods operating in planes above and below and substantially parallel to the dead plate and adapted to move cases thereover, the spacing of the push rods being substantially in excess of the case dimension in the direction of movement, means for driving the principal conveyor, a delivery con veyor and a receiving conveyor aligned with the principal conveyor and dead plate, said dead plate being arranged downstream from the receiving conveyor to receive delivery of cases therefrom, the receiving conveyor and dead plate being disposed below the path of movement of the push rods and within the space between the sprocket chains, yieldable stop means associated with the dead plate to position a case delivered thereon, the adjacent ends of the delivery and receiving conveyors being separated to provide space for the push rods to move upwardly therebetween, means for continuously driving the delivery and receiving conveyors, the lineal speed of travel of the receiving conveyor being in excess of the lineal speed of the principal conveyor, whereby a case delivered to the receiving conveyor will be advanced ahead of an oncoming push rod, means timed with the travel of the push rods for moving a case directly from the delivery conveyor onto the receiving conveyor prior to the passage of a push rod upwardly between the ends of the receiving and delivery conveyors, whereby a case will be moved onto the receiving conveyor and, by such conveyor, immediately moved onto the dead plate and against the yieldable stop means to remain for an interval before the oncoming push rod reaches the trailing end of the case to advance it past the yieldable stop means and beyond the treating station.

4. In a cover flap opening mechanism for top-opening cases having cover flaps hinged to swing rearwardly, the combination of a flap raising station, a conveyor having spaced pushers for advancing individual cases in spaced relation to and beyond the flap raising station with the flap hinge lines arranged transversely of the conveyor travel and on the trailing sides of the cases, means for driving the conveyor, means for stopping the individaul cases in position at said station, auxiliary conveying means for advancing each case ahead of its pusher as the case approaches said station until brought to a stop by said stop means at the station, a flap raising mechanism at said station, means timed with the pusher travel for actuating the flap raising mechanism while the case is at said station to raise the case flap and hold it inclined at a small angle, a flap swinging member disposed at a level above the case at said station but within the path of the case flap when raised, said member extending transversely of the direction of conveyor travel to support the flap in raised position when the case, with raised flap, is advanced, the pusher in original '1 1 contact with the case serving to propel the case away from said station, said flap swinging member acting, upon advancing movement of the case, to swing the flap over to a rearwardly extended position.

5. In a cover flap opening mechanism for top-opening cases having cover flaps hinged to swing rearwardly, the combination of a flap raising station, a principal conveyor having a series of spaced pushers for advancing individual cases in spaced relation to and beyond the flap raising station with the flap hinge lines arranged transversely of the conveyor travel and on the trailing side of the cases, means for driving said conveyor at a constant speed, means for stopping the individual cases in position at said station, an auxiliary conveyor, means for driving such conveyor at a speed in excess of that of the principal conveyor for advancing each case ahead of its pusher as such case approaches said station until brought to a stop by said stop means at the station, a flap raising mechanism at said station, means for actuating the flap raising mechanism while the case is at the station to raise the case flap and hold it inclined at a small angle, a flap swinging member disposed at a level above the case at said station but within the path of the flap when raised, said member extending transversely of the direction of conveyor travel to support the flap in raised position when the case, with raised flap, is advanced, the pusher in original contact with the case serving to propel the case away from said station, said flap swinging member acting, upon advancing movement of the case, to swing the flap over to a rearwardly extended position.

6. In a cover flap opening mechanism for a rectangular, four-wall, top-opening case formed of paperboard and having cover flaps hinged on the upper edges of its walls, the combination of a principal conveyor having a series of case-engaging pushers spaced apart a distance substantially in excess of the case dimension to move cases separately along a fixed path, means for driving such conveyor, a flap raising station including means for lifting the trailing case flap through a small angle, an auxiliary conveyor located upstream from the Hap raising station to deliver cases to such station, means for operating the auxiliary conveyor at a speed in excess of that of the principal conveyor to advance a case to the flap raising station substantially ahead of an oncoming pusher on the principal conveyor, means for stopping a case delivered by the auxiliary conveyor in operative position relative to the flap raising means, a flap swinging element located at an appreciable distance downstream from the leading edge of the trailing case flap, brought to rest at the flap raising station, to be clear of the fiap as it is raised, said element serving to swing the flap to open, rearwardly extended position when the case is advanced past such element, and control means timed with the principal conveyor for actuating the flap raising means and for holding same in operative condition until a pusher on the principal conveyor has advanced the case a sufiicient distance to enable the leading edge portion of the trailing flap to pass above the flap swinging element.

7. A conveyor system for rectangular cases and similar articles designed to deliver cases separately to and beyond a treating station, comprising, in combination, a base, a dead plate on the base for supporting cases to be treated, a principal conveyor on the base comprising a plurality of spaced, transversely disposed push rods operating in a plane above and substantially parallel to the dead plate and adapted to move cases thereover, the spacing of the push rods being substantially in excess of the case dimension in the direction of movement,

means for driving the principal conveyor, a delivery conveyor and a receiving conveyor aligned with the principal conveyor and dead plate, said dead plate being arranged downstream from the receiving conveyor to receive delivery of cases therefrom, the receiving conveyor and dead plate being disposed below the path of movement of the push rods, yieldable stop means associated with the dead plate to position a case delivered thereon, means for continuously driving the delivery and receiving conveyors, the lineal speed of travel of the receiving conveyor being in excess of the lineal speed of the principal conveyor, whereby a case delivered to the receiving conveyor will be advanced ahead of a noncoming push rod, means timed with the travel of the push rods for releasing a case from the delivery conveyor onto the receiving conveyor ahead of an oncoming push rod, whereby a case will be moved onto the receiving conveyor and by such conveyor moved onto the dead plate and against the yieldable stop means to remain for an interval before the oncoming push rod reaches the trailing end of the case to advance it beyond the treating station.

8. In a cover ilap opening mechanism for top opening cases having a cover flap hinged to swing rearwardly, the combination of means for advancing a case along a path transverse to the cover flap hinge line and with the flap hinge disposed on the trailing side of the case, a flap raising and swinging station, means for bringing a case to a stop at such station, a flap raising mechr'iism at said station, said mechanism comprising a vacuum cup freely supported at the lower end of a depending, flexible conduit, said conduit being supported on a lifting means attached to the conduit at a point above the case path and substantially outside the arc described by the free edge of the flap when swinging to rearwardly extended position, means for lowering said lifting means while the case remains at rest to allow the vacuum cup readily to engage the flap, means for activating said vacuum cup, and means for thereafter raising the lifting means to raise the flap through a small angle, a flap swinging member comprising a rod disposed above the path of the case but within the path of the case flap when raised, said rod extending transversely of the direction of the advancing case to support the flap in raised position when the case with its raised case flap is advanced, means for moving the case in a direction away from the station, means timed with movement of the case to deactivate the vacuum cup upon advance of the free edge of the case flap to a position over said rod, said rod acting upon subsequent movement of the case to swing the flap over to a rearwardly extended position, the depending vacuum cup and conduit being adapted to be readily displaced by the case flap as it is swung to rearwardly extended position.

References Cited by the Examiner UNITED STATES PATENTS 1,106,618 8/1914 Bernheim 1 198-23 2,369,575 2/1945 Kay 198-23 2,890,560 6/1959 Nigrelli et al. 53-382 2,902,810 9/1959 McGihon 53-374 2,918,773 12/1959 Krupp et a1. 53-382 2,997,833 8/1961 Nigrelli et a1. 53-382 3,015,923 1/1962 Dotzenroth 53-381 X 3,075,332 1/1963 Krupp et al 53-382 GRANVILLE Y. CUSTER, 111., Primary Examiner.

' ROBERT A. LEIGHY, TRAVIS S. McGEHEE, FRANK E. BAILEY, Examiners. 

4. IN A COVER FLAP OPENING MECHANISM FOR TOP-OPENING CASES HAVING COVER FLAPS HINGED TO SWING REARWARDLY, THE COMBINATION OF A FLAP RAISING STATION, A CONVEYOR HAVING SPACED PUSHERS FOR ADVANCING INDIVIDUAL CASES IN SPACED RELATION TO AND BEYOND THE FLAP RAISING STATION WITH THE FLAP HINGE LINES ARRANGED TRANSVERSELY OF THE CONVEYOR TRAVEL AND ON THE TRAILING SIDES OF THE CASES, MEANS FOR DRIVING THE CONVEYOR, MEANS FOR STOPPING THE INDIVIDUAL CASES IN POSITION AT SAID STATION, AUXILIARY CONVEYING MEANS FOR ADVANCING EACH CASE AHEAD OF ITS PUSHER AS THE CASE APPROACHES SAID STATION UNTIL BROUGHT TO A STOP BY SAID STOP MEANS AT THE STATION, A FLAP RAISING MECHANISM AT SAID STATION, MEANS TIMED WITH THE PUSHER TRAVEL FOR ACTUATING THE FLAP RAISING MECHANISM WHILE THE CASE IS AT SAID STATION TO RAISE THE CASE FLAP AND HOLD IT INCLINED AT A SMALL ANGLE, A FLAP SWINGING MEMBER DISPOSED AT A LEVEL ABOVE THE CASE AT AID STATION BUT WITHIN THE PATH OF THE CASE FLAP WHEN RAISED, SAID MEMBER EXTENDING TRANSVERSELY OF THE DIRECTION OF CONVEYOR TRAVEL TO SUPPORT THE FLAP IN RAISED POSITION WHEN THE CASE, WITH RAISED FLAP, IS ADVANCED, THE PUSHER IN ORIGINAL CONTACT WITH THE CASE SERVING TO PROPEL THE CASE AWAY FROM SAID STATION, SAID FLAP SWINGING MEMBER ACTING, UPON ADVANCING MOVEMENT OF THE CASE, TO SWING THE FLAP OVER TO A REARWARDLY EXTENDED POSITION. 